Method of bending back rigid printed wiring board with flexible portion

Abstract

A method for bending back a rigid printed wiring board with a flexible portion includes: forming a preparation substrate on a surface of a prepreg made of thermosetting resin, the preparation substrate including a conducting layer made of a conductive material; laminating the plurality of preparation substrates; thermally hardening the thermosetting resin so as to integrate the plurality of laminated preparation substrates as an intermediate substrate while heating and pressing together the plurality of preparation substrates; cutting an insulating layer formed by thermally hardening the thermosetting resin in a lamination direction of the preparation substrate so as to form a flexible portion, the flexible portion being thinly formed across opposed both edges of the intermediate substrate to form a complete substrate; bending the flexible portion; bending-back the flexible portion; and dehydrating by raising a temperature of the bent flexible portion before bending-back the flexible portion.

1 . A method for forming a printed wiring board with a flexible portion, comprising:
 a preparing step comprising forming a plurality of preparation substrates on a surface of an approximately flat plate-shaped prepreg made of a thermosetting resin, the preparation substrate including a conducting layer as a circuit pattern made of a conductive material;   a laminating step comprising laminating the plurality of preparation substrates;   a thermally hardening step comprising thermally hardening the thermosetting resin so as to integrate the plurality of preparation substrates laminated at the laminating step as an intermediate substrate while heating and pressing the plurality of preparation substrates one another;   a cutting step comprising cutting an insulating layer formed by thermal hardening the thermosetting resin at the thermally hardening step in a lamination direction of the preparation substrate so as to form a flexible portion, the flexible portion being thinly formed across opposed both edges of the intermediate substrate to form a complete substrate;   a bending step comprising bending the flexible portion;   a bending-back step comprising bending-back the flexible portion bent at the bending step; and   a dehydrating step comprising dehydrating the flexible portion bent in the bending step before the bending-back step.   
     
     
         2 . The method for forming a printed wiring board with a flexible portion according to  claim 1 , further comprising:
 an inspection step comprising performing an energization inspection on the complete substrate before the dehydrating step, and   a repairing step comprising repairing the complete substrate after the bending-back.